Year	kg per hectare
1961	2905.7
1962	3259.6
1963	3312.8
1964	3330.1
1965	3775.6
1966	3565.5
1967	3557.3
1968	3627.1
1969	3716.6
1970	3911.8
1971	3911.5
1972	3951.3
1973	4080
1974	3840.4
1975	3978.1
1976	3941.1
1977	3923.8
1978	4019.3
1979	3964.2
1980	4094.5
1981	4100.5
1982	4203.7
1983	4321.1
1984	4347.5
1985	4539.2
1986	4696.2
1987	4891.6
1988	5028.8
1989	5337.7
1990	5702.9
1991	5613
1992	5898.5
1993	5995.1
1994	5861.1
1995	5903.7
1996	6499.1
1997	6605.5
1998	6797.4
1999	7166.6
2000	7280.1
2001	7099.4
2002	7445.6
2003	7515.4
2004	7556.2
2005	7536.9
2006	7500.2
2007	7418.5
2008	7452.2
2009	7158.3
2010	6504.3
2011	7246.3
2012	7269
2013	7285.3
2014	7085
2015	7117.3
2016	7251.5
2017	7400.6
2018	6776
2019	6047
2020	7166.1
2021	7338.5
2022	7418.5